Robin's Dad - Gold Roger?

Think about it...Robin has black hair. Her mom has blond hair. Gold Roger has black hair.
Gold Roger reads ancient texts.
Robin's father is briefly mentioned but he may have been a rather powerful guy.

If Roger and Luffy are related, Luffy may find a relative in Robin too, which would be quite the twist.

The only thing is the surname doesn't fit, but it may have been deliberately changed?

Think about it...Robin has black hair. Her mom has blond hair. Gold Roger has black hair.
Gold Roger reads ancient texts.
Robin's father is briefly mentioned but he may have been a rather powerful guy.

If Roger and Luffy are related, Luffy may find a relative in Robin too, which would be quite the twist.

The only thing is the surname doesn't fit, but it may have been deliberately changed?

First of all what has hair color got to do with anything? Hair color could be inherited from anyone in the family and black hair is common so how can you link Robin and Roger together just because of that!?
As for Roger, Luffy and Robin being related I don't think it will be that simple.

I think if Robin was related to Gol D roger her name would be Nico D Robin

Not necessarily. We have yet to meet a woman with D. in the middle, so it could technically be a title only given to men. Even if women can obtain it, we can't be sure whether or not all the children receive it, or only the ones with 'the will of D'.

Anyway, the proof you gave was far from sufficient. We don't know enough about the many mysteries of One Piece to even debate stuff like this.

Think about it...Robin has black hair. Her mom has blond hair. Gold Roger has black hair.
Gold Roger reads ancient texts.
Robin's father is briefly mentioned but he may have been a rather powerful guy.

If Roger and Luffy are related, Luffy may find a relative in Robin too, which would be quite the twist.

The only thing is the surname doesn't fit, but it may have been deliberately changed?